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A database is a system intended to organize, store, and retrieve large amounts of data.

A record is a unit of a database file made up of related filds.

A field is a single piece of information in a reord.

A relational database is a database that separate, related fileds, but combines data elements from the files for queries and reports.

A query is a tool that allows you to extract information that meets certain criteria.

data summary example.docx

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Example:

Normal Form:

1. First Normal Form (no columns of data or duplicate rows of data)

2. Second Normal Form (each attribute is dependent on the entire primary key)

3. Third Normal Form ( each attribute is only dependent on the primary key)

2NF Table.docx

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A relation is a data structure which consists of a heading and an unordered set of tuples which share the same type.

When Edgar F. Codd invented the relational model, he generalized the concept of binary relation (mathematical relation) to n-ary relation.

Relation is a fundamental concept in relational model.

A relation has zero or more tuples. A relation value is an instance of a relation.

A relation variable (relvar) is a variable which has a relation value.

ER Diagram

Basic ER- Diagram.docx

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